html {
  /* 使用一种可以i正确设置元素宽度和高度的CSS盒子模型,即宽高包括padding  border */
  box-sizing: border-box; 
}
*, *::before, *::after {
  box-sizing: inherit;
}
body, input {
  font: menu;
}
html,  body {
  height: 100%;
  width: 100%;
  overflow: hidden;
}
body {
  margin: 0;
  padding: 0;
  position: absolute;
}
textarea, input, div, button {
  outline: none;
  margin: 0
}
.controls {
  background-color: rgb(217, 241, 238);
  padding: 10px;
  display: flex;
  justify-content: space-between;
}
button {
  font-size: 14px;
  background-color: rgb(181, 220, 216);
  border: none;
  padding: .5em 1em;
}
button:hover {
  background-color: rgb(156, 198, 192);
}
button:active {
  background-color: rgb(144, 182, 177);
}
button:disabled {
  background-color: rgb(196, 204, 202);
}
.container {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  min-width: 100vw;
  position: relative;
}
.content {
  height: 100vh;
  display: flex;
}
.raw-markdown, .render-html {
  display: inline-block;
  min-height: 100%;
  max-width: 50%;
  flex-grow: 1;
  padding: 1em;
  overflow: scroll;
  font-size: 16px;
}
.raw-markdown {
  border: 5px solid rgb(238, 252, 250);
  background-color: rgb(238, 252, 250);
  font-family: monospace;
}